The LXT360 and LXT361 are the first full-featured, fully integrated, combination transceivers for E1 ISDN Primary Rate Interface and T1 long- and short-haul applications. They operate over 0.63 mm (22 awg) twisted-pair cables for 0 to 2 km (6 kft) and offer Line Build-Outs and pulse equalization settings for all T1 and E1 Line Interface Unit (LIU) applications. The LXT360 and LXT361 are identical except for their control options. The LXT361 offers an Intel or Motorola compatible parallel port for microprocessor control. The LXT360 provides both a serial port for microprocessor control and a hardware control mode for stand alone operation. Both incorporate advanced crystal-less digital jitter attenuation in either the transmit or receive data path starting at 3Hz. B8ZS/HDB3 encoding/decoding and unipolar or bipolar data I/O are available. Both LIUs provide loss of signal monitoring and a variety of diagnostic loopback modes.